Apparatus for continuous casting of metal



D. B. COFER ET AL APPARATUS FOR CONTINUOUS CASTING 0F METAL Filed Dec.50, 1963 Oct. 18, 1966 4 Sheets-Sheet 1 C Y m I PQ AT TORNE Y8 Oct. 18,1966 c R ET AL 3,279,000

APPARATUS FOR CONTINUOUS CASTING 0F METAL 4 Sheets-Sheet 2 Filed Dec.30, 1963 INVENTORSI Dame! 5. COM

Dale D. Proctor BY George C. Ward ATTORNEYS Oct. 18, 1966 Filed Dec. 30.1963 D. B. COFER L APPARATUS FOR CONTINUOUS CASTING 0F METAL 4Sheets-Sheet 3 INVENTORS: Daniel B. Cofer Dale D. rector P BY G or e C.rd M 1% RNEYS V Oct. 18, 1966 FER ET AL 3,279,000

APPARATUS FOR CONTINUOUS CASTING OF METAL Fiied Dec. 30. 19s: 7 4Sheets-Sheet 4 H IHI l n nu INVENTORS: Damel B. Cofer BY Dale D. ProcioGeorge C. W

Q Jw a Mg ATTORNEYS United States Patent 3,279,000 APPARATUS FORCONTINUOUS CASTING 0F METAL Daniel B. Cofer, Dale D. Proctor, and GeorgeC. Ward,

Carrollton, Ga., assignors to Southwire Company, Carrollton, Ga., acorporation of Georgia Filed Dec. 30, 1963, Ser. No. 334,197 22 Claims.(Cl. 2257.4)

This invention relates to apparatus for continuous casting of metal andis more particularly concerned with a continuous casting machine inwhich different metals may be cast and which is particularly suited forthe casting of copper into a continuous rod suitable for subsequentlybeing rolled in a rolling mill, then drawn into wire.

In the past, continuous casting wheels or drums have been employed forcasting aluminum bars which have subsequently been drawn into aluminumwire. Indeed, many patents have been issued to Ilario Properzi andothers relating to such casting wheels and equipment employedinconjection therewith. US. Patent No. 2,865,- 067 illustrates generallythe type of prior art casting wheel to which we refer.

These prior art casting Wheels have included a rotatable drum having agrooved periphery, around a portion of which a steel endless beltpasses, the belt being of greater length than the circumference of thedrum and diverging therefrom on opposite sides. Hence, there is formedan inlet into which molten metal is poured and an exit from which thesolidified rod (or bar) is withdrawn. The core or central portion of thedrum is hollow to permit the circulation of a coolant, such as water.

When such prior art devices are employed for casting copper, the copperis cooled slowly and as a rule is discharged in an unevenly cooledcondition. That is to say that, periodically along the length of thedischarged copper, there are dark spots and light spots which apparentlyalfect the internal structure of the copper rod to an extent that in thesubsequent rolling operation, the copper rod is not sufiiciently ductileto permit its reduction to small diameter wire.

We believe that the uneven cooling of the prior art casting drum is dueto the fact that the water coolant is relatively in a quiescentcondition adjacent the inside surface of the casting wheel and thesudden heating of this water adjacent the inside surface as the moltenmetal passes thereby causes a portion of the water to flash boil, thevapors being carried around with the wheel for a short distance and thenbeing collapsed. The flash boiling removes the water from an incrementof the casting wheel and the subsequent condensation of the steampermitting the water again to contact the increment as anotherincrement. This sets up a pulsating situation for the water which causesuneven cooling of the increments and also causes the cooling to beslowed to an extent that the prior art casting wheel is impractical forcasting copper rods. Thus, it has generally been believed that thecontinuous casting of copper for subsequent drawing to wire size isimpossible or impractical.

The prior art literature has suggested that the conductivity of a copperrod is the function of the initial density of the bar or rod from whichthe wire is rolled or drawn, the conductivity being directlyproportional to the density of the cast bar or rod. Hence, it wouldappear to be desirable in order to produce a copper wire having as highconductivity as possible to control the conditions under Patented Oct.18, 1966 "ice which the bar or rod is cast so as to produce as dense acasting as possible. Furthermore, a more dense bar or rod would requireless mechanical Working in order to produce the more dense wiretherefrom.

In the past, cooper has been cast in situ inblock or bar form in a moldwhich is left in ambient air to cool. Under such conditions the coppertends to cool from the sides and bottom slowly, thereby creating thedendritic crystalline structure on three sides; however, the upperportion of the copper appeared to have a spongy structure which ishoneycombed with small voids or gas spaces. The density of this copperbar is approximately 8.47-8.59. If such a copper bar were cooled fromall sides, the .concentration of the spongy structure or small voids inthe structure would be toward the central of the bar. The voids orspongy structure interfere with the subsequent drawing of the copperand, in general, tend to make the bar less capable to being drawn intofine wire.

Briefly, the apparatus of the present invention which tends to obviatethe problems described above includes a disc-shaped inner flange whichis supported concentrically at the end of a rotatable shaft and extendsradially therefrom in all directions. A ring shaped or annular castingwheel or member is removably clamped to the front face of the innerflange by a spring loaded outer flange, the spring loading of whichpermits the casting member to expand and contract with thermal changes.The casting member is provided with a casting groove in its outerperiphery while the inner periphery and sides thereof have cooling finswhich provide for the rapid dissipation of the heat from the castingmember. To facilitate this rapid and even cooling of the molten metaland reduce to a minimum the tendency of the coolant to flash boil,circumferentially spaced jet nozzles are disposed along the inner andouter peripheries of the casting member, the outer jet nozzles directingthe coolant again-st an endless belt, of greater length than thecircumference of the casting member, as it partially circumscribes thecasting member for closing the open portion of the casting cavity orgroove. The inner nozzles direct the coolant against the inner peripheryof the casting member and the side nozzles direct the coolant againstthe sides of the casting member. By such an arrangement the copper orother molten metal, which is continuously poured into the inlet formedby the belt and casting member as they meet, is cooled so rapidly thatthe gases which would normally create the voids are not given sufiicienttime to form. Thus, an even dense bar of copper emerges from the exit,the copper having a density suflicient for being drawn into fine wire.

Accordingly, it is an object of the present invention to provide acontinuous casting machine which is particularly suited for castingcopper rod having characteristics which permit the subsequent drawing ofthe rod into fine wires.

Another object of the present invention is to provide a continuouscasting machine in which the cooling of all sides of the cast metal maybe selectively controlled,

Another object of the present invention is to provide a continuouscasting machine in which the element defining the casting cavity may bereadily and easily replaced and is so retained that thermal changes donot set up stresses in the machine.

Another object of the present invention is to provide a continuouscasting machine which is capable of quickly and evenly cooling moltenmetal immediately after it is received in the casting machine.

Another object of the present invention is to provide, in a continuouscasting machine, an efiicient means by which the incremental cooling ofthe motlen metal may be controlled.

Another object of the present invention is to provide a continuouscasting machine which is capable of casting a continuous metal rod frommolten metal directed into the casting machine, the metal rod having adense, relatively uniform crystalline structure and being of a crosssectional configuration more suitable for subsequent reduction in crosssection.

Another object of the present invention is to provide, in a continuouscasting machine, a cooling system which will quickly and eflicientlycool the molten metal and casting ring of the casting machine withoutappreciable flash boiling of the coolant.

Another object of the present invention is to provide a continuouscasting machine which is inexpensive to manufacture, durable instructure and eflicient in operation.

Other objects, features andadv-antages of the present invention willbecome apparent from the following description when taken in conjunctionwith the accompanying drawings wherein like characters of referencedesignate corresponding parts and in which:

FIG. 1 is a front elevational view of a continuous casting machineconstructed in accordance with the present invention, parts thereofbeing broken away.

FIG. 2 is an enlarged side elevational view, partially in cross-section,of one of the jet nozzles employed in the continuous casting machineillustrated in FIG. 1.

FIG. 3 is a cross-sectional view taken substantially along line 3-3 inFIG. 1.

FIG, 4 is a vertical cross-sectional view of the continuous castingmachine shown in FIG. 1.

FIG. 5 is a cross-sectional view of the peripheral portion of thecasting machine illustrated in FIG. 1 and showing a modified formcasting cavity having trapezoidal cross-section.

FIG. 6 is a diagrammatical representation of the automatic control forthe cooling system of the present invention.

Referring now in detail to the embodiment chosen for the purpose ofillustrating the present invention, it being understood that in itsbroader aspects the present invention is not limited to the exactdetails herein depicted, numeral 10 denotes a central horizontallyextending shaft which is appropriately journalled by a base 11 forrotation about its axis, the shaft being driven by a prime mover, suchas a motor (not shown). The shaft 10 defines the central transverse axisof the machine illustrated. Forwardly of the base 11, the end of shaft10 is provided with a flat, disc shaped, radially extending, face plate12.

The central portions of shaft 10 and face plate 12 are provided with aninternally threaded axial bore 13 which threadedly receives one end of acylindrical stub shaft 14, the other end of which protrudes along thetransverse axis of the machine beyond face plate 12 and is externallythreaded to receive the nut 15. Nut 15 and washer 16 retain a bearingsleeve 17 on the shaft 14 and urge it against the central portion offace plate 12 for rotation therewith.

Surrounding the rear portion of sleeve 17 and secured by bolts 18 to thefront or forward surface of face plate 12 is an innerflange 19 which isa disc shaped member having a circular periphery 20. The inner flange 19is appreciably larger in diameter than the face plate 12 and its frontsurface, adjacent periphery 20, is provided with an annular groove 21.As best seen in FIG, 3, the groove 21 is defined by concentric inner andouter walls, the inner wall being deeper than the outer wall so that thebase position of groove 21 tapers outwardly and forwardly between theconcentric walls. Since the groove 21 is spaced inwardly of theperiphery 20, the periphery and groove 4 21 define, therebetween, aforwardly extending shoulder 22.

For forming an envelope to receive the molten metal, the inner flange 19carries a casting member 30. The casting wheel or member 30 is formedfrom copper, and is a ring shaped member, having a transversely flatouter periphery within the central portion of which is an annularperipheral casting groove 31 for receiving molten metal. Incross-section, casting groove 31 is defined by a pair of inwardlyconverging opposed flat sides 32 and 33 which converge toward the radialaxis of the machine'and subtend an angle of approximately 10 degreestherebetween. The casting cavity 31 has either an arcuate, con-, cavebottom 34, as seen in FIG. 3, or a flat bottom 134, as seen in FIG. 5.The flat bottom 134 has curved extremiti es which merge with the innerend portions of sides 32 and 33, while the rounded, concave bottom 34 issubstantially hemisphericalto provide end portions which themselvesmerge tangentially (or essentially tangentially) with the inner ends ofsides 32 and 33.

The forward and rear sides of the casting member 30 are provided with aplurality of diminishing diameter concentric grooves which definetherebetween a plurality of spaced, axially extending, annular side fins35 and 36 from the periphery of the member 30 inwardly to the, region ofthe central portion of member 30. The central portion of the innerperiphery of casting member 30, in like manner, is provided with innerfins 37 which are spaced axially from each other and are disposedradially parallel to each other.

- Adjacent the inner periphery and protruding in opposite directions,i.e., forwardly and rearwardly from .the sides of casting member 30, area pair of peripheral shoulders 38 and 39, the inner sides of which areextensions of the inner periphery of casting member 30 and the outersides of which are concentric with, but of larger diameter than, theinner sides. The faces of the shoulders taper outwardly so that thetaper of the face of rear shoulders 39 conforms to the taper of the baseportion of groove i an annular outer flange 40 which is carried by theinner flange 19 andryieldably urged against the outer side of castingmember 30. In more detail, the outer flange 401 is a flat, annularmember of substantially the same thick:

ness and outer diameter as the inner flange 19. The rear surface offlange 40 is provided with an annular groove 41 which is opposite to andcomplementary with groove i 21 of inner flange 19 and receives shoulder38 of the casting member 30. The flange 40 thence extends inwardlybeyond the casting member 30 sufficiently to receive therethrough aplurality of circumferentially spaced, parallel stove bolts 42 whichprotrude through the inner flange 19, inwardly of the casting member 30.The bolts.

42 are sufficiently long that they protrude forwardly, i.e., axially,beyond flange 40 and are each provided with a helical spring 43. One endof spring 43 is received in a counterbored recess in flange 40surrounding bolt 42,; and the other end engages a washer 44 and urges itagainst a nut 45 on the end of bolt 42. Hence, at all times, the castingmember 30 is yieldably clamped between inner flange 19'and outer flange40 and is permitted limited expansion and contraction since the springs,such as spring 43, will permit the outer flange 40 to move forwardly andrearwardly while being urged rearwardly toward flange 19 into itsclamping position.

The inner periphery of outer flange 40 is grooved appropriately for, andreceives one side of, and annular inner shield 46 which protrudesforwardly to terminate in about the same plane with the forward ends ofbolts 42.

The front surface, outwardly of bolts 42, receives an outer annularshield 47, which is concentric with the inner shield 46. Between theinner shield 46 and outer shield 47, and spaced forwardly of flange 40and outwardly of bolts 42, is an intermediate annular shield 48 which iscarried by the periphery of a front plate 49 which extends over theinterior of the machine, the front plate 49 being disposed slightlyforwardly of the front edge of shield 46.

The drum described above is rotated in a clockwise direction asindicated by the arrow in FIG. 1. As best seen in FIG. 1, the usualend-less, flat, flexible, metal belt 50, of greater length than thecircumference of the drum described above, passes around approximately180 degrees of the drum and then passes around an idler drum (notshown). Since the idler drum for belt 50 and drive mechanism for shaftare shown in such patents as U.S. Patents Nos. 2,865,067; 2,659,948;2,710,433 and 2,659,- 949, these features are not illustrated in thepresent application. The belt 50 is approximately the same width as thewidth of the casting member 30 and functions to close the outer side ofthe outwardly opening casting cavity 31, progressively moving to form acontinuously formed, open ended, arcuate, tubular member or envelopehaving an inlet at approximately the 45 degree position of the castingmember 30 and an exit at approximately the 225 degree position of thecasting member 30.

As will be understood by those skilled in the art, molten metal from apouring pot 51 is introduced by gravity, by way of a spout 52 into thecasting cavity 31, at the inlet of the tubular member, as the belt 50closes the outer side of the casting cavity 31. After being cooled andtransported in an arcuate path, the cast metal is discharged as acontinuous cast rod 53 from the exit end of the tubular member, as thebelt 50 diverges from the casting member 30. During the period of travelalong the lower portion of the casting member 30, the casting member andbelt 50 are subjected from all sides to cooling as will be pointed outhereinbelow.

Cooling system According to the present invention, the cooling systemfor quickly solidifying the molten metal received in casting cavity 31,and for further cooling the empty casting member 30 includes a pluralityof jet nozzles disposed on the three sides of the casting member 30 andon the fourth side defined by the belt 50. Each group of jet nozzlesdirects a high velocity stream of coolant, such as water, against thecasting member 30 or belt 50 in such quantity that there is very littleopportunity for the coolant, i.e. water, to be vaporized to any greatextent, the jet nozzles being so distributed that the cast metal iscooled evenly to a prescribed surface temperature at the time ofdischarge, and the casting member 30 is further cooled to present a coolsurface for receiving additional molten metal.

For supplying coolant to the inner periphery of the casting member 30,an inner cooling system is provided with three separately or selectivelycontrolled, circumferentially disposed cooling stages having a commoninner header or manifold, denoted generally by the numeral 55. Theheader 55 is a closed, hollow, annular member having a hub or collar 56which circumscribes the bearin g sleeve 17, being spaced therefrom byanti-friction bearings 57 and 58. Front and rear, spaced, parallel,circular plates 59 and 60 are secured .to 'the ends of collar 56 andextend radially therefrom. The peripheries of these plates 59 and 60 arejoined by a cylindrical cap 61.

Within the header 55 are three radially extending divider plates 62, 63and 64, seen in FIG. 4. Plate 62 is disposed upright While plate 63 isdisposed approximately 150 degrees therefrom, and plate 64 is disposedat approximately 2'20 degrees from palte 62. Thus, three separatecompartments are provided in the inner header 55.

Spoke-like hollow pipes 65, 66 and 67 radiate from the cap 61 and arereceived by an annular base member 68 of the hollow outer header 70.Pipes 65 communicate with the first compartment of the header 55, thepipes 66 communicate with the second compartment of header 55 and thepipes 67 communicate with the third compartment of header 55. The outerheater 70 includes an outer annular cap or spray ring 71 concentric withthe base member 68 and a pair of side walls 72 and 73 which connect thesides of the base member 68 and the annular cap 71. The outer header 70is provided with three baflie plates 74, 75 and 76 which separate theouter header 70 into three separate compartments, the plate 74 beingdisposed upright and the plate 75 and 76 being disposed 135 degrees and270 degrees therefrom.

The outer cap 71 is provided with spaced holes disposed approximately 10degrees from each other, the holes being internally threaded to receive,respectivly, the jet nozzles 77 which are angled in a clockwisedirection at approximately 45 degrees from the radius. As illustrated inFIG. 2, each jet nozzle 77 includes a 45 degree elbow 78 to which ismounted a flat spray nozzle 78a having a body with a jet orifice 79 anda deflector 80, such as that disclosed in U.S. Patent No. 2,530,671.Each nozzle 77 is arranged to direct the coolant angularly outward toimpinge upon the inner periphery of the casting member 30 at a position17 degrees advanced in a clockwise direction from the outlet of thenozzle 77.

It will be understood that the inner and outer headers 55 and 70 aredisposed concentrically with respect to casting member 30 and theheaders 55 and 70 are within the confines of the drum, as defined by theinner flange 19 and the front plate 49. Three coolant supply pipes 81,82 and 83 supply coolant, such as water, respectively, to thecompartments of the inner header 55.

The pipes '81, 82 and 83 are respectively provided with control means,such as valves 84, 85 and 86, by which the amount of coolant flowing toa particular compartment may be varied as desired. Pipes 81, 82.and 83are so arranged that they pass through the front plate 49 and providesupport therefor. Pipes 81, 82 and 83 terminate at the front plate 59 ofheader 55 and are in communication, respectively, with appropriate holesleading to the three compartments of the header 55. Hence the headers 55and 70 do not rotate but remain fixed as the drum, including castingmember 30, rotates thereabout.

It will be understood that the pipe 81 communicates with the compartmentdefined by divider plates 62 and 63, the pipe 82 communicates with thecompartment defined by divider plates 63 and 64 and the pipe 83 is incommunication with the compartment defined by divider plates 64 and 65.

The spokes or hollow tubes 65, 66 and 67 provide communication betweenrespective compartments of the inner and outer headers 55 and 70;therefore, the coolant from pipe 81, after entering the compartment ofthe inner header 55 passes outwardly therefrom through the threespoke-like tubes 65 into the first stage compartment of the outer header70, as defined by divider plates 74 and 75 Thence, the coolant issprayed by the group of jet nozzles 77 which are disposed from 0 degreesto 135 degrees of the arc of the outer header 70 and constitute thefirst stage cooling means.

The coolant from pipe 81 is directed by the nozzles 77 against thebottom of successive increments of rotating casting member 30 as theincrements approach the zone to receive the molten metal from spout 52,and as the increments travel approximately degrees immediately afterreceiving the molten metal.

Since much of the heat of the molten metal must be dissipated during thefirst quarter revolution of the casting member 30 after receiving themolten metal, the pipe 81 is relatively large, hence the volume of waterdelivered to nozzles 77 of the first cooling stage is relatively large.The coolant impinges upon the area of fins 37 at acute angles to thepath of travel and is deflected, or cascades,

downwardly, being collected at the bottom portion of the machine untilit overflows around the shields 46 and 47.

In the second cooling stage, the pipe 82 communicates with a compartmentof the inner header 55 so as to feed coolant through two tubes 66 to theouter header 70, thence through the nozzles 77 which communicate withthe compartment between bafiies 75 and 76. As in the preceding stage ofcooling, the water from thesesecond stage nozzles 77 is directed againstthe fins 37 for cooling the metal from the time it passes the firstcooling stage until it emerges from the exit as solid rod 53 at aposition of approximately 270 degrees as the drum is viewed in FIG. 1.At this point, if the metal is copper, the metal bar 53 should be redhot, or about 1800 degrees F.

It is desirable, between the time an increment of the casting member 30releases the bar 53 and the time an increment is positioned forreceiving the molten metal, to cool the casting member 30 further sothat it is relatively cool when the molten metal is received. Thus, athird stage of cooling is provided wherein the coolant from theremaining nozzles 77,i.e. the nozzles disposed from 270 degrees to 360degrees with respect to the drum, direct the coolant against the fins37. The pipe 83 communicates with the compartment between divider pates64 and 62 for supplying this coolant through tubes 67 to the compartmentbetween divider plates 76 and 74, thence to the third stage nozzles 77.

The coolant from the two latter stages of cooling also collects in thebottom portion of the drum and drains therefrom in the same way thecoolant from the first stage drains therefrom.

By varying the openings of valves 84, 85 and 86 the temperature ofincrements of the casting member 30 can be varied to achieve controlledcooling of the molten metal, as well as controlled cooling of thecasting member 30.

To supplement the internal cooling system described above, and to coolthe metal more evenly from the time it is received until it isdischarged as bar 53, side cooling systems are provided whichsimultaneously direct the coolant inwardly against opposite sides of thecasting member 30. Also a belt cooling system directs coolant againstthe outer surface of the belt 50 as it passes around casting member 30.

The side cooling systems include a pair of arcuate pipes 90 and 91disposed on opposite sides of the casting member 30 from approximately90 degrees to 250 degrees of the drum, these pipes 90 and 91 conformingto the curvature of the casting member 30. All nozzles 92 and 93 (whichare each identical to nozzle 77) are threadedly carried by the pipes 90and 91, respectively, and direct coolant in tangential planes inwardlyfrom pipes 90 and 91, the coolant being directed in a clockwisedirection (as viewed in FIG. 1.) inwardly so as to impinge upon andbetween the fins 35 and 36 at acute angles. The pipes 90 and 91 areprovided with valves 94 and 95 whereby the amount of coolant directedagainst each side of the casting member 30 may be controlled. Hence, theside cooling systems supply a predetermined amount of coolant to bothsides of successive increments of the casting member 30 from the timeimmediately prior to the time the increments release the metal as rod'53.

The belt cooling system includes an arcuate pipe 96 having a valve 97,the pipe 96 being disposed concentrically outward of that portion ofbelt 50 which is disposed around casting member 30. Nozzles 98, (whichare each identical to nozzle 77) project inwardly and in a clockwisedirection, as viewed in FIG. 1, for directing coolant against the outersurface of increments of the belt 50 from the time the increments of thebelt 50 (cooperating with the casting wheel 30) receive the molten metaluntil immediately prior to the time the increment of belt 50 releasesthe metal as rod 53. The last few nozzles, i.e. the last two nozzles98a, are preferably directed in a counterclockwise direction inwardly soas to retard the spray of coolant along the line of travel of belt 50 asthe 'belt 50 diverges from casting member 30. I

Above the position at which the belt 50 diverges from the casting memberis the usual extractor shoe 99 supported by a bracket 100 in the path oftravel which the rod 53 could take if it were retained in the castingcavity 31. The function of this shoe 99 is to deflect the bar 53outwardly in the event the bar 53 adheres to the cavity 31.

The mechanism thus far described is disposed in a suitable well in aplant and is supported by the floor 101 of the well. are appropriatelysupported by brackets such as brackets 102 extending upwardly from floor10 1 and by brackets, such as brackets 104, which project from wall 103of the well.

Automatic control for cooling system As seen in FIG. 6, the flow of thecoolant may, if desired be automatic and controlled in accordance withthe temperature of the metal rod 53 as it emerges from the castingwheel. To accomplish this, a thermocouple type pyrometer 200 is mountedon a suitable support (not shown) adjacent the rod 53 for viewing thesame as it emerges from the casting member 30. Electrical electricallyconnected to a variably positionable brush.

207 on the resistor 208 of a potentiometer 209. An additional resistor210 is arranged in parallel with the resistor 208 and these resistors208 and 210 are arranged in parallel with a resistor 211 of a first legof a Wheatstone bridge, denoted generallyby numeral 212.

The first leg of the Wheatstone bridge 212 also has a resistor 213 inseries with the parallel disposed resistors 208, 210 and 211.

The second, third and fourth legs of the Wheatstone bridge 212 arerespectively provided with resistors 214, 215 and 216, the resistors211, 213 and 214 constituting one side of the bridge 212 and theresistors 215 and 216 constituting the other side thereof.

A source of constant voltage, such as a standard electric cell 217 isconnected across the junction of resistors 213 and 214 to the junctionof resistors 215 and 216 while a wire'218 leads from the junction ofresistors 214 and 215 to the control mechanism 203.

It will be understood that, initially, the main control circuit, whichincludes the conduit 201, pyrometer 200 conduit 202, potentiometer 209,bridge 212 and wire 218, is designed to provide a zero potential whenthe pyrometer 200 reads a prescribed temperature, such as 1800" F. Anincrease or decrease in this prescribed temperature will increase ordecrease the potential outi put of the pyrometer 200 and unbalance themain circuit to provide a current flow, in one direction if a highertemperature is read and a current flow in the opposite.

direction if a lower temperature is read.

The main control circuit, in turn, signals the control mechanism 203 tocontrol the feed of current, via wires. 206 to motor 205 to control theactuation and deactuation of the motor 205, as well as the direction ofrotation of the motor 205. In other words, if the current flows in onedirection in the main control circuit, it will dictate that the controlmechanism 203 direct current to the motor 205 for causing it to rotatein one direction and if current flows in an opposite direction, in themain circuit, the control mechanism 203 directs current to The pipes 81,82, 83, 90, 91 and 96 gen or free hydrogen may also be present. Sinceall these components produce gases, the voids are created because of thepresence of these gases in the metal which is cooled from the outside.The presence of minor amounts of gases in the prior art processes ofcasting copper create what is known as tough pitch copper and isdesirable in such prior art processes.

In the process of the present invention, however, the presence of suchgases is undesirable and essentially eliminated, giving a dense copperrod 53 which requires less rolling in order to produce a copper wirehaving the usual density of from 8.87 to 8.94 without the necessity ofworking the copper sufficiently to eliminate or weld the voids.

The rod 53 which we have produced is relatively small with respect tothe prior art, in situ cast bar, the bar 53, if trapezoidal, such asthat produced from cavity 131, measuring, in cross-section, along itsmajor base (the base adjacent belt 50) from approximately 1% inches toapproximately 2 inches and preferably 1 inches. The converging sides ofthe bar 53, in cross-section, are likewise from approximately 1% inchesto approximately 2 inches and preferably 1 ,4 inches while the minorbase is from approximately inch to approximately 1% inches andpreferably 1 inch exclusive of the curvature radii. If, on the otherhand, the rod 53 has a crowned inner side, such as if the bar 53 werecast in cavity 3 1, the base thereof i.e., the portion adjacent belt 50would measure from approximately 1% inches to approximately 2 inches andpreferably 1.8 inches while the sides would measure from approximately 1/3 inches to approximately /3 inch and preferably 1.25 inches, and thedepth of the bar measures from 1 inch to 2 inches, being preferably 1.6inches. The radius of curvature of the crown would then be fromapproximately inch to inch and preferably /2 inch.

Since the coolant is directed from four sides against the casting member30 and against the belt 50, the molten metal within the casting cavity31 is, likewise, cooled from all sides.

This creates from the molten metal poured into the mold or castingcavity 31 or 131, a solidified rod 53 having an acicular grain structurein which the crystals are progressively larger from all sides inwardly.These crystals are oriented generally perpendicular to the surfacesadjacent thereto. Hence, in a typical cross-section of the trapezoidalrod 53, the crystals which are adjacent the opposite sides of rod 53,are oriented in generally parallel planes, and protrude inwardly to acentral trunk portion disposed perpendicular thereto. The crystals whichare adjacent the major base and minor bases are disposed in planesperpendicular to the planes of the crystals adjacent the sides. Witheven cooling from all sides, diagonal branch lines which extenddivergently from the ends of the central trunk, separate the sidecrystals from the base crystals. Thus, a tree-like appearance isproduced wherein the trunk of the tree is generally centered between thesides of the cast metal and branches extend generally diagonally to thecorners of the cast metal. This dendritic structure, we have found, iscapable of being worked in the rolling mill, and drawn to create smalldiameter wire.

It will be remembered that the casting member 30 is preferably made fromcopper itself and because of the rapid cooling of the molten metal, andbecause of the precooling of the casting member 30, immediately beforeit receives the molten copper, there is little danger of the castingmembers being heated sufliciently at any time to weld to the copper rod53 as it is formed. The spray within the interior of the drum, aspointed out above, is directed in clockwise direction and hence thecoolant which collects in the bottom portion of the drum is urged inclockwise direction and overflows at a position beyond the 180 positionso as to pass out of the drum by flowing over the flange 40, and overthe shields 46 and 47.

Because of the high volume of coolant introduced into the interior ofthe drum by the pipes 81, 82 and 83, the level of the coolant within thedrum may build up, thereby increasing the flow of the coolant from thedrum. Any coolant which cascades between the headers 55 and 70 and theback flange may readily pass through the open area between the spokes65, 66 and 67 and, therefore, there appears to be no concentration ofthe coolant within the drum in any uneven distribution.

The fins 35, 36 and 37 permit a rapid cooling of the casting member 30,thereby drawing out the heat from the metal within the casting cavity 30at a rate appropriate to provide the dendritic structure of the typewhich has the trunk portion of the structure centered toward the centerof the rod 53. Furthermore, the casting member being of copper permitsthe rapid conduction of the heat away from the casting cavity 31.

If it is found that the structure of the cast rod or bar 53 is uneven,indicating more cooling on one side than another, the appropriate valveor valves, such as valves 84 and 97, may be opened or closed partiallyto adjust for the desired amount of cooling along a particular side.Further, if the rod or bar 53 emerges from the casting member 30 at atemperature different from the desired temperature, the valve 86 may bemanipulated to alter this temperature. Furthermore, if the portion ofthe casting member 30, which is to be cooled immediately prior toreceiving the molten metal, is at a higher or lower temperature thandesired, manipulation of the valve 86 will result in an adjustment ofthis temperature.

With the speed of the casting member properly adjusted, the volume ofthe coolant properly adjusted and the temperature and the flow of themolten metal properly adjusted, the machine will function with littleattention.

When the mechanism is to be operated automatically, all manual controlvalves 84, 85, 86, 94, and 97 are opened. This permits the valve 222 orthe valve 223, to control the quantity of water fed to the castingwheel. The pyrometer 200, as explained above, controls motor 205 which,in turn, controls the amount of opening of the valve 222. Therefore, ifthe temperature of the surface of rod 53 is too high, the pyrometer 200signals motor 205 to move valve 222 toward a more opened condition and,conversely, when the temperature of the surface of rod 53 is too low,the pyrometer 200 signals the motor 205 to move valve 222 toward aclosed condition.

The bypass valve 223 serves two functions. First, it may be partiallyopened and operated in conjunction with valve 222 so that the valve 222simply controls the flow of an increment of the water in pipe 224.Secondly, in the event of a shut down of the automatic control system,it may be opened completely so that the water is entirely under thecontrol of valves 84, 85, 86, 94, 95 and 97. 7

Furthermore, the automatic control of the water by valve 222 does notpreclude the utilization of the valves 84, 85, 86, 94, 95 and 97 forbalancing the distribution of the water, as described above.

It will be obvious to those skilled in the art that many variations maybe made in the embodiments here chosen for the purpose of illustratingthe present invention without departing from thescope thereof as definedby the ap-. pended claims.

We claim:

1. In a continuous casting machine, a rotatable shaft, an inner circularflange carried by said shaft for rotation therewith, an outer circularflange spaced from said inner flange, spring means connecting said outerflange to said inner flange, and an annular casting member releasablycarried between said inner flange and said outer flange, said annularcasting member protruding outwardly of the peripheries of said outerflange and said inner flange and having a contniuous casting cavityabout its outer periphery.

2. In a continuous casting machine, a rotatable shaft,

the motor 205 for causing it to rotate in an opposite direction.

As seen in FIG. 6, a linkage 220 is provided between the motor 205 andthe brush 207 whereby, when motor 205 rotates, it moves the brush 207along the resistor 208 in a direction for zeroizing the main controlcircuit. Thus, when the main control circuit is balanced, the movementof the brush 207, the motor 205 will be stopped.

When the pyrometer is reading a large temperature differential from theprescribed temperature, it generates a relatively high potential whichrequires greater movement of brush 207 to balance. Therefore, motor 205will be rotated to a greater extent before brush 207 is properlypositioned to return the main control circuit to a zero potential. It isnow seen that the rotation of motor 205 is proportionally responsive tothe surface temperature of rod 53 as read by pyrometer 200.

The motor 205 is connected to and controls, via linkage 221, .a maincontrol valve 222. The main control valve 222, together with a manualbypass valve 223 is interposed in the line of a main pipe 224 from asource of coolant under pressure, such as water from a water main (notshown). The pipe 224 leads to the various manual control valves 84, 85,86, 94, 95 and 97.

Operation From the foregoing description, the operation of the presentmachine should be apparent. It is suitable for the continuous casting ofquite a number of molten metals into rods. Specifically, the machine issuitable for casting aluminum, copper, zinc, lead and alloys thereof.The operation of the machine, therefore, will be described with respectto copper, since this is by far the more dilficult metal to cast in aform which may be reduced to wire size, and presents a novel way ofcasting copper. When utilizing the machine of the present invention forcasting a continuous copper rod or bar, such as rod 53, it is desirablethat the rod 53 be delivered from the machine as hot as possible withoutdanger of the metal being molten within the central portion thereof,when the rod 53 is delivered to a rolling mill (not shown). Thus we havefound that the copper rod 53 should have a surface temperature (asmeasured by pyrometer) when it emerges from the machine, ofapproximately 1750 F. and between the range from approximately 1600 F.to approximately l8-,50 F. Above approximately 1980 F. copper is in amolten state and hence a substantially lower surface temperature shouldbe maintained so as to assure that essentially no molten metal exists inthe core or central portion of the rod 53.

When the machine is to be operated, the shaft 10 is rotated in clockwisedirection, as viewed in FIG. 1, at a speed such as to impart aperipheral velocity to the casting member 30 of between 30 and 60 linearfeet per minute. The belt 50 is driven by the casting wheel at a likespeed and circumscribes from approximately 45 to approximately 225 ofthe casting member 30. The belt converges toward the casting member 30at the 45 inlet position and diverges therefrom at the 225 outletposition. Next, the valves of the cooling system are opened after moltencopper is introduced into the groove 31.

It will be remembered that the third stages'of the internal coolingsystem, i.e., the cooling from 270 to 360 of arc of the casting member30, is for the purpose of reducing the temperature of the upperincrements of the casting member 30. Preferably the temperature isreduced to a temperature of from 400 to 450 F. The purpose of reducingthe temperature of the upper increments of the casting member 30,immediately prior to the time that it receives the molten metal, is toincrease the life of the casting member 30 and to present a relativelycool surface to the molten metal. ,The casting member 30, however,should be maintained at a temperature in excess of the 1 0 boiling pointof the coolant, so that the casting cavity 31 i is dry when it receivesthe molten metal.

During the period in which the belt 50 is not in contact. with thecasting member 30, the casting cavity 31 is open and the inside surfaceof the belt 50 is accessible. A part ing or releasing agent iscontinuously applied to the insidr surface of belt 50 and to the surfaceof the casting cavity. 31 so that the resulting cast metal rod 53 willreadily par. from the casting cavity 31. While a number of releasing orparting agents are available, we recommend that. soot be employed tocoat the casting cavity 31 and the inside surface of the belt 50immediately prior to the time that these members receive the moltenmetal.

At the 45 position of casting member 30, the molten metal, such asmolten copper, is fed from the pot 51,; through the spout 52, into theentrance or inlet of the tubular member formed by the convergence of thebelt 50 and the casting cavity 31. The metal is prevented from flowingout of the casting cavity 31 by the belt 50 which closes the open sidethereof. Hence the molten. metal runs down the right side of the castingcavity, as viewed in FIG. 1, and is solidified so as to build up a basefor receiving additional molten metal. When such a base is built up, themolten metal can be received continuously in the inlet of the castingcavity 31. The first stage cooling, i.e., the cooling from 0 to 13:5" ofthe arc of the casting member 30, cools the molten metal, i.e., copper,from approximately 2200 F. (the temperature at which the molten metal isintroduced into the casting cavity 31) to a temperature of approximately1980 F., at which time the copper commences to solidify. This isaccomplished in only a few seconds after the copper is received at theinlet.

i is solidified slowly,

The purpose of cooling the metal rapidly is to convert the molten metalinto a solid having as small a grain structure as is feasible and toprevent internal voids due. to shrinkage of the metal upon coolingslowly.

As mentioned above, the prior art bar which is cast horizontally in acasting cavity, usually has a density of approximately 8.47 toapproximately 8.59 and is subsequently rolled and drawn into the wirehaving the density of from 8.87 to 8.94. The prior art bar, as cast, iscooled relatively slowly so that the gases therein create a fiat orcrown set to the upper surface, rather than a concave set or shrinkagecavity. The bar having a concave upper surface is difficult to rollbecause of the sharp edges at the upper surface.

Contrary to prior art beliefs and practices, the copper cast in themachine of the present invention is cooled quickly enough to produce acasting having an average overall density of 8.83, i.e., a densitybetween approximately 8:75 and approximately 8.89. This copper rod hasfew, if any, voids or gas holes and essentially no sponge-like structureas would normally be found in horizontally cast copper.

The copper utilized in either case is 99.90%+ pure copper, the majorportion of the impurities therein being oxygen in the form of copperoxide. Tlhere also are trace amounts of hydrogen and sulphur containedin the molten present invention contemplates metal. The process of thethe freezing or solidfying of the molten metal from approximately 2200F. down to below 1980 F., i.e., to approximately 1750 F. within a veryshort copper rod which is essentially free of any voids. Theoreticallly, by utilizing such a procedure the oxygen in the copper oxideis not given suflicient' time to disassociate and/or combine with thehydrogen or sulphur to produce a gas. a

While the reaction which has taken place, when copper is not understoodcompletely by us, it has been suggested that the oxygen of the copperoxide combines with trace amounts of sulphur so as to produce sulphurdioxide, and with trace amounts of hydrogen to produce water vapor. Ofcourse, some free oxy- I period of time, appmoximately two seconds, soas to produce a dense a circular inner flange mounted on said shaft forrotation therewith, an annular flange yieldably mounted on said innerflange, an annular casting member carried between the peripheries ofsaid flanges and protruding outwardly therebeyond, said casting memberhaving a continuous outwardly opening casting cavity in the outerperiphery thereof, a continuous metal belt partially encompassing saidcasting member and converging toward and diverging from the outerperiphery of said casting member, said belt closing the outer side ofcasting cavity between the positions of convergence and divergence ofsaid belt, means for introducing molten metal into said cavity adjacentthe position where said belt converges toward said casting member, aplurality of circumferentially spaced nozzles disposed adjacent theinner periphery of said casting member, conduit means leading from asource of coolant to said nozzles for supplying controlled amounts ofcoolant to said nozzles, a pair of groups of side nozzles disposedadjacent to the sides of said casting member for cooling that portion ofsaid casting member which is partially encompassed by said belt and apair of pipes leading respectively to said groups of said side nozzles.

3. In a continuous casting machine, a rotatable shaft, a circular innerflange mounted on said shaft for rotation therewith, an annular flangeyieldably mounted concentrically on said inner flange, an annularcasting member carried between the peripheries of said flanges andprotruding outwardly therebeyond, said casting member having acontinuous outwardly opening casting cavity in the outer peripherythereof, a continuous metal belt partially encompassing said castingmember and converging and diverging from the outer periphery of saidcasting member, said belt closing the outer side of said casting cavitybetween the positions of convergence and divergence of said belt, aplurality of groups of circumferentially spaced nozzles disposedadjacent the inner periphery of said casting member for directingcoolant outwardly and circumferentially toward said inner periphery, aplurality of pipes leading from a source of coolant respectively to saidgroups of nozzles for supplying controlled amounts of coolant to each ofsaid groups of nozzles, a pair of groups of side nozzles disposedadjacent to the sides of said casting member for cooling that portion ofsaid casting member which is partially encompassed by said belt, a pairof pipes leading respectively to said groups of said side nozzles, agroup of belt cooling circumferentially spaced nozzles disposed in anarcuate path outwardly adjacent that portion of said belt whichpartially encompasses said casting member, a pipe for supplying coolantto said belt cooling nozzles, control means for controlling the amountof coolant fed to each group of nozzles, and means for feeding moltenmetal into the said casting cavity at a position adjacent the positionat which said belt converges toward said casting member.

4. In a casting machine; an annular member having an inner surface, anouter surface, two side surfaces extending between said inner surfaceand said outer surface, and a casting groove in said outer surface;closing means for closing a length of said casting groove so that saidclosing means and said casting groove define a mold to receive moltenmetal; support means for supporting and rotating said annular memberabout an axis so that segments of said mold move along an arcuate path;a header having a chamber positioned within said inner surface of saidannular member; means for dividing said chamber into a plurality ofcompartments disposed in sequence along said path; means for providing acoolant to each of said compartments; and cooling means for dischargingsaid coolant from each of said compartments against said inner surfaceof said annular member.

5. The casting machine of claim 4 wherein at least two differentquantities of said coolant are simultaneously 14 discharged from saidcompartments against said inner surface of said annular member. 7

6. The casting machine of claim 5 wherein said difierent quantities areindependently variable. I

7. The castings machine of claim 5 wherein one of said quantities isapplied at an initial portion of said path and is greater than the otherof said quantities.

8. The casting machine of claim 7 wherein said one of said quantities issufiicient to cool molten metal in said mold at a rate greater than anyrate elsewhere along said path.

9. The casting machine of claim 4 including a plurality of finsextending from said inner surface of said annular member toward saidcooling means for discharging said coolant from each of saidcompartments.

10. The casting machine of claim 4 wherein said cooling means fordischarging said coolant from each of said compartments include aplurality of nozzles positioned to discharge said coolant from saidcompartments against said inner surface of said annular member.

11. The casting machine of claim 4 wherein said cooling means fordischarging said coolant from each of said compartments includes aplurality of nozzles positioned to direct jets of said coolant from saidcompartments against said inner surface of said annular member.

12. The casting machine of claim 11 wherein said jets are directed inpaths which are angularly disposed to said inner surface of said annularmember.

13. The casting machine of claim 11 wherein said jets are directed inpaths inclined to said inner surface of said annular member in thedirection in which said inner surface moves as said angular member isrotated about said axis by said support means.

14. The casting machine of claim 4 wherein said means for dividing saidchamber into a plurality of compartments is a plate positioned withinsaid chamber to divide said chamber.

15. The casting machine of claim 4 including second cooling meansdisposed adjacent said annular member for applying said coolant to oneof said side surfaces of said angular member, and third cooling meansdisposed adjacent said annular member for applying said coolant to theother of said side surfaces of said angular member.

16. The casting machine of claim 15 including means for selectivelyvarying the quantity of said coolant applied to said one of said sidesurfaces .by said second cooling means independently of the quantity ofsaid coolant applied to said other of said side surfaces by said thirdcooling means.

17. The casting machine of claim 15 including fourth cooling meansdisposed adjacent said annular member for applying said coolant to saidclosing means.

18. The casting machine of claim 17 including means for varying thequantity of said coolant applied by said fourth cooling meansindependently of the quantity of said coolant applied by said secondcooling means, the quantity of said coolant applied by said thirdcooling means, and the quantity of said coolant applied by said coolingmeans for discharging said coolant against said inner surface of saidannular member.

19. The casting machine of claim 4 including spray means disposedadjacent said annular member for spraying said coolant on said closingmeans.

20. The casting machine of claim 19 wherein said spray means includes anarcuate tubular member having a plurality of nozzles along its lengthpositioned to direct jets of said coolant against said closing means.

21. The casting machine of claim 20 wherein the paths of at least someof said jets are inclined to said closing means in the direction inwhich said angular member moves as said annular member is rotated aboutsaid axis by said support means.

22. The casting machine of claim 21 wherein the paths of others of saidjets are inclined to said closing means in a direction opposite to saiddirection in which said 15 16 annular member moves as said annularmember is rotated 2,743,492 5/1956 Easton 22 -79 about sard axrs by sardsupport means. FOREIGN PATENTS References Cited by the Examiner 764,19312/ 1956 Great Britain. UNITED STATES PA N S 5 861,273 2/1961 GreatBritain.

944,370 12/ 1909 Monnot 22200.1 X T 2,206,930 7/1940 Webster 22 57 3 J.SPENCER OVERHOLSER, Pnmary Exammer.

2,246,907 6/1941 Webster 22--57.3 X R. S. ANNEAR, Assistant Examiner.

4. IN A CASTING MACHINE; AN ANNULAR MEMBER HAVING AN INNER SURFACE, ANOUTER SURFACE, TWO SIDE SURFACES EXTENDING BETWEEN SAID INNER SURFACEAND SAID OUTER SURFACE, AND A CASTING GROOVE IN SAID OUTER SURFACE;CLOSING MEANS FOR CLOSING A LENGTH OF SAID CASTING GROOVE SO THAT SAIDCLOSING MEANS AND SAID CASTING GROOVE DEFINE A MOLD TO RECEIVE MOLTENMETAL; SUPPORT MEANS FOR SUPPORTING AND ROTATING SAID ANNULAR MEMBERABOUT AN AXIS SO THAT SEGMENTS OF SAID MOLD MOVE ALONG AN ARCUATE PATH;A HEADER HAVING A CHAMBER POSITIONED WITHIN SAID INNER SURFACE OF SAIDANNULAR MEMBER; MEANS FOR DIVIDING SAID CHAMBER INTO A PLURALITY OFCOMPARTMENTS DISPOSED IN SEQUENCE ALONG SAID PATH; MEANS FOR PROVIDING ACOOLANT TO EACH OF SAID COMPARTMENTS; AND COOLING MEANS FOR DISCHARGINGSAID COOLANT FROM EACH OF SAID COMPARTMENTS AGAINST SAID INNER SURFACEOF SAID ANNULAR MEMBER.